Gray breads varieties effect on the vegetable residues balance in Central Siberia agrocenosis

The aim of the study is to assess the impact of different varieties of spring barley and oats on the balance of plant residues in agrocenoses of Central Siberia. The study was carried out in 2017–2019 on leached chernozems, ordinary and podzolized state cultivar plots of the Krasnoyarsk Region. The accumulation of plant residues in agrocenoses was influenced by soil fertility, weather conditions, fertilizers, biological and varietal characteristics of plants. In the forest-steppe and subtaiga zones of the region, the differences between the maximum and minimum yields of spring barley were 3.6 times and oats – 1.5 times. The average yield of different varieties of barley in field experiments was 3.75 t/ha and oats – 3.23 t/ha. After harvesting, 8.05–8.21 t/ha of plant residues entered the soil. According to the intensity of the accumulation of plant residues, the varieties of spring barley Biom and Krasnoyarskiy 91 are distinguished, and for oats – Sayan and Tubinskiy. In an equivalent amount with plant residues of barley and oats, from 4.0 to 4.1 t/ha, calculated as bedding manure, enter the soil. The highest amount of plant residues in terms of manure (5.76–5.82 t/ha) returns to the soil at the Uyarsk variety plot and the smallest (2.59–3.49 t/ha) – at Sayansky and Kazachinsky. Among the varieties of spring barley, Biom and Krasnoyarsk 91, and oats – Sayan and Tubinsky, prevail in terms of the intensity of manure entering the soil. The amount of nutrient removal by bar-ley and oats is influenced by the value of crop yields. On average, with yields of different varieties of barley, 251.5 kg/ha of nitrogen, phosphorus, potassium is removed from the soil, and with different varieties of oats – 223.1 kg/ha of the above macronutrients. When embedded in the soil with plant residues, 54.3–55.3 kg/ha of nitrogen, phosphorus, and potassium return. Compensation for the removal of nutrients through the use of plant residues of gray crops for fertilization is 21.7–24.2 %.